I have two partitions - one with Mac OS, and another with Windows 7 (created by Bootcamp). Now, I want to create two more partitions for Linux - LINUX and LINUXSWAP. I open Disk Utility and specify new partitions using + button in the mas disk. Then I click apply. Application returns strange message partition failed with the error: couldn't modify partition map because file system verification failed. I googled for that problem and everywhere people advice to repair disk using boot CD with MacOS which leads to deinstalling all applications, perhaps, losing windows partition and very time consuming. I don't like this way. Do you have an idea how I can create just two partitions for my Linux?

  • Disk Utility shouldn't affect your Windows partition or installed applications, even when used on the system drive.
    – Nilloc
    Nov 1 '11 at 17:30
  • Did you ever find a solution to this? i have the same issue would be much appreciated if you could share anything?
    – user14852
    Dec 12 '11 at 14:11
  • Nope, I tried to create a partition using win7 and it led to braking macos partitioning - so finally I reinstalled macos. Dec 16 '11 at 7:55

There might be a misconception somewhere in what you say. You can run Disk Utility from the original system disc WITHOUT re-installing OS X.

I ran into a similar problem recently, on which running Disk Utility from any of the existing partitions would not work. I then tried running Disk Utility from a restore disk I had copied to an external USB-drive and to my surprise it was not successful either. Ultimately, the only way I was able to get Disk Utility to re-partition my drive was when I executed it from the original system CD that shipped with my Mac.

Again, you can launch Disk Utility from the setup start up screen by selecting it from one of the menus. You do not require to re-install OS X. Hope this helps.


Background: To create the extra partitions, the current Mac OS partition, which probably occupies all space on the disk, needs to be reduced in size. Disk Utility can resize Mac OS volumes, but only if they have no logical errors on them.

What you described sounds like your Mac OS volume was having errors. You should have let Disk Utility repair the volume. This doesn't necessarily lead to losing files. Often, it's only a little inconsistency on the disk that Disk Utility fixes without any problems. Only if Disk Utility would then say that it can't repair it, you'd need to consider saving your files to another disk and then reformat your disk. But if all is repaired, then you could go back and add the extra partitions.

Also, if you really know what you're doing (this is rather directed to others as the originally asking person surely isn't), you can use a tool like iBored to manually mess with the partition table to make room. Expect data loss if you don't know what that means, though :)


The best way to add, remove, or modify partitions if you aren't a tech guru is to use disk utility. If disk utility fails the best thing to try is using the OS X DVD or on Lion the recovery partition. You do not have to reinstall the operating system to use this method. The OS X DVD can be used to run disk utility or to reinstall the operating system. Select disk utility from the DVD or the recovery partition and repair the disk and disk permissions. Once it is finished try to partition the disk again.

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